For the sake of self-consistency, the main technical details of the
AIMD simulations are recalled here. They were performed by means
of the Vienna Ab initio Simulation Package (VASP) [1]}.
The local density approximation (LDA) [2]}, [3]}
within projected augmented plane-waves was applied to all simulations
with a plane-wave cutoff of 241 eV. For the liquid states, only
the \(\Gamma \) -point is used while for crystalline states, the
\(\Gamma \) -centered grid of \(k\) -points in the irreducible part of the
Brillouin zone was set to \(2\times 2\times 2\)  following the
Monkhorst–Pack scheme [4]}, [5]}. All the
simulations were performed with \(N = 256\)  atoms placed in a cubic
simulation box (except for the hcp crystal where an orthorombic box
was used) with standard periodic boundary conditions (PBC). Newton’s
equations of motion were solved numerically with Verlet’s algorithm
in the velocity form with a time step of \(1.5\)  fs, and phase-space
trajectories were constructed within the canonical ensemble (NVT),
by means of a Nosé thermostat to control the temperature \(T\) . The
temperature evolution in the undercooled states was obtained by
quenching the system stepwise down to 600 K with a temperature
step of 50 K. For each temperature, the simulation cell was resized
according to the experimental density [6]} and the run
was continued for 30 ps before performing the next quench,
resulting in an average cooling rate of \(3.3\times 10^{12}\)  K/s. The
calculated pressures for all the temperatures studied here were
less than \(\pm 1\)  GPa generally, so that on average a quasi constant
pressure during the quenching is observed. For temperatures ranging
from \(T = 1000\)  K to 600 K, the run was continued for equilibration
during a time up to 200 ps. A similar procedure was applied for
heating the fcc crystal from 10 K to 900 K.
